The present invention relates to novel 1,2-diamino derivatives of cyclobutene 3-4-diones having pharmacological activity, to a process for their preparation, to pharmaceutical compositions containing them, and to their use in the treatment of disorders associated with smooth muscle contraction; via potassium channel modulation. Such disorders include, but are not limited to: urinary incontinence, hypertension, asthma, premature labor, irritable bowel syndrome, congestive heart failure, angina, and cerebral vascular disease.
Stemp et at. disclose a class of amino substituted cyclobutenedione derivatives of chromans described as having blood pressure lowering activity and bronchodilatory activity in EP-426379-A2. Several series of 1-amino-2-phenylalkylamino-cyclobutene-3,4-diones are reported as H-2 receptor antagonists by Algieri et at. in U.S. Pat. No. 4,390,701. Several related 1-amino-2-phenoxyalkylamino derivatives are disclosed by Nohara et at. in U.S. Pat. No. 4,673,747.
The syntheses of variously substituted 1,2-diamino-cyclobutene-3,4-diones are described in the following publications: Tietze et at., Chem Ber. 1991, 124, 1215; Tietze et at., Bioconjugate Chem. 1991, 2, 148; Ehrhardt et al., Chem. Ber. 1977, 110, 2506, and Neuse et at., Liebigs Ann. Chem. 1973, 619.